1. Field of the Invention
The present invention relates to an aircraft actuator control apparatus including a plurality of hydraulically operated actuators that drive a control surface of an aircraft and a plurality of control systems that respectively control the operation of the plurality of actuators.
2. Description of Related Art
Conventionally, aircraft actuator control apparatuses are used that include a plurality of hydraulically operated actuators that drive a control surface of an aircraft and a plurality of control systems that respectively control the operation of the plurality of actuators. A known example of such an aircraft actuator control apparatus is the aircraft actuator control apparatus disclosed in JP 2003-40199A.
In the aircraft actuator control apparatus disclosed in JP 2003-40199A, control systems each including control valves (a first control valve 351, a second control valve 352) and a state switching valve (a damping delivery valve 357) are provided for each actuator. The control valves are configured to control the operation of each actuator by switching between the paths of pressure oil that is supplied to and discharged from a pair of oil chambers in the actuator. The state switching valve, which is installed between the control valves and the actuator so as to connect the control valves to the actuator, includes an orifice that can be in communication with the pair of oil chambers of the actuator, and is configured to switch the operating state of the actuator.
The above-described state switching valve is provided such that its position can be switched between a position to connect the actuator to the control valves such that pressure oil flows between each of the pair of oil chambers of the actuator and the control valves and a position in which the pressure oil discharged from the pair of oil chambers can pass through the above-described orifice. Note that in a state where the state switching valve is switched to a position in which pressure oil flows between the actuator and the control valves, the supply path and the discharge path of the pressure oil to and from the pair of oil chambers are switched by the control valves, and thereby the operation of the actuator is controlled. On the other hand, in a state where the state switching valve is switched to a position in which the pressure oil discharged from the pair of oil chambers can pass through the orifice, the pair of oil chambers are in communication via this orifice, and thereby the damping function is fulfilled.
Also, the pressure oil is supplied to the plurality of actuators from the respective aircraft central hydraulic power sources that are configured as different systems. Then, if a loss or degradation in the function occurs in the hydraulic power source that supplies the pressure oil to one of the actuators, the state switching valve corresponding to that actuator is switched to the position to provide communication between the pair of oil chambers via the orifice. Accordingly, the above-described damping function is fulfilled, and thereby the actuator that experiences a degradation or the like in the function of the corresponding hydraulic power source operates so as to follow an external force exerted on the control surface. This can prevent an operation to impede the operation of an actuator for which a loss or the like in the function of the hydraulic power source has not occurred and prevent an abnormal operation, including, for example, excessive movement of the control surface, such as flutter.